Hard rubber



i May 30, 1933. Q, GURNEE` 1,911,566

BBE

Filed March 17, 1932 Patented May 3o, 1933 l 1,911,566

UNITED STATES PATENT OFFICE y I I Y ISAAC actriz-NEE., or Burana, NEW Jiiii-SEY 'd i l Y HARD RUBBER. ARTICLE YAlvin Mn'riaon MAKING'THE siiivinv v' E j applicati@ mediteren 17, ieaa'jserialiitjteasi. l v p f n' My invention relates to new and usef-ul -Y F ig. y5 is a transverse section through the improvenientsgin Ahard rubber blocks and Completed article; 1 method of making the same, and has for Fig. 6 is a perspective of the completed i an object to provide a hardrubber block article; Y n E "5 that may be produced in a rapid manner Fig.' 7 is a plan view,"the dotted lines, 55' and, at the same time, will keepV desired however,`showing abulge which would ocshape, that is,.will not bulge or blow, as cur if'the block were niadewithout the use is technically known to those'skilled in the of the small core.

,A art, A Referring now more particularly to the '10 n Still another object 'of the invention is to Several views and for the moment to Fig. 1 60 produce a hard rubber blockin which there there is shown 'the rubber stock which has,`

is an upper threaded chamber-so that a been run through a rod and tubingmachine, certain electrical device may be placed therethere being the cylindrical Vbore l, the openin, this latter, however, in no way entering ing 2' and what I termv a bleeder holeV 3. L into the spirit of the present invention.V This 'rubber stock is then to be cut off in 65 Still another object of they invention` is to blocksalong the dotted linesl, so that they produce a hard rubber block-which is to be may be placed in amold, shortly tobe provided with an internally threaded upper mentioned. f

, chamber and -is also to be provided with av In Fig. 3, I have shown a fragmentary be described..

sniall'passageway through the base, so that portion of a mold 5, in which may be seen the gases may escape while the rubber is onefofthe blocks which has been cut olf being molded Vto thus preventl the bulging from thestock, as y'above outlined, and partly or blowing`of the article, as will shortly cured and pressed to shape. *f

Fitting within the passageway l of the Still another object of the invention is" block 6 is shown the chamber core 7 which 75d fee to produce a method of molding ahard rubis threaded, as lat VA8, and has vthe protruding ber block wherein the'same may be taken @11d 9.k The Teer end 0f the Core may be cut out of the molds while still in a heated conout, as atl 10, so that the core may exactly dition and then placed in a vulcanzel for the blOC-k the COI'I'GC'v dlSl'iaIlG. the nal hea-t, thus permitting the articles 'ljhllsyf Chamber 7' S Omed for the recep-` t0 be molded in a, relatively SHOM, tima tion of an electrical device (not shown).

With these and other' obj'ects in View, the There Will BSO. be IlOCed. another core invention consists in certain new and novel llfhet S t0 be fitted Within the bleeder helle arrangements and combination of parts, as 3 Ofthe-dblocki'ds may ,bdseen 'illustrated 85 will be hereinafter more fully described and in Fg- 3- pointed out in the Claims It will be understood that when the block Referring. DOW to the drawno, is secured in the mold and heated, it will Fig. l isi a perspective ofa st'ip of softv messed to the .Shape Shown Fig'. 3

o rubber stoclrthat hasbeen run through a 2 sldeblikOvjllggslaazvhe 90 rod and tubing machine and is to be diadqthefblckrnow r' -d th vided, as indicated, into blocks; p ovl e W1 l e ex '45' canizing operation;

tending'lugs` 12 at its base. lqFlg- 2 hovs alblok Wlth Lhe Coles m AI havelfound that thebloclrniay be left p ce remy or t le rst moldmg or 'Vul' inthe mold in itsirst operation for twenty F0 3 in t 1 A minutes and atone hundred pounds presle-l 1S; e ldglden dry P en VleW ef a sure, so that the blockjwill be partly cured mold Sddwmg Jd1@ met modding @Perdtlon when removed. d AfterV hese twenty minutes Fig. 4 is a similar plan with the small core it'. isf-taken Oui,` of the molds While in its 1101;V removed to allow the gases to escape from condition..

the block, that is, during the final curing; l `It mig-ht beinentioned here that owing to 100 the thickness of the block, gas forms inside the blocks when vulcanized with quick short heats, and it is only by the provision of the bleeder hole 3 with the core 11 placed therein that makes it possible to be able to remove the block after being in the mold for only twenty minutes. I v Y, Y j

There is another advantage in being able to remove the partly cured block from the mold in twenty minutes, as if the article is left in the mold or a much greaterlength of time, it begins to show shrinkage. j

Reverting again to the steps of the process, the article is then put in a vulcanizer with a pressure of preferably sixty-five pounds and is allowed to remainl for six and one-half hours which completely cures the block. v o

In this instance, it will be seen, however, (Fig. 4) that the core 1l is not placed within the hole 3, so that the gases that have formed in the b ase of the block may readily escape through this bleeder hole 3,

It will be understoodthat if it. were not :tor the core-ll in the bleeder hole,3,`the gases would start to form 'in the block during the first molding operation and the blocks, when' put in the vulcaHiZer,` would blow upand form the bulge, as shown by the dottedj'lines 13 in Fig. 7. However', by providing this' core 11 and a bleeder hole 3, the gases may partly escape around the care 1lV in the rst molding operation while in the second operation, this is, during the vuleanizing for iinal curing,'thecore'1l being left lout,"the gases may readily escape from the block, so that when the article is completely` cured its contours will be perfect and fthere` willlbe no bulging orblowing inthe relativelyv thick base or upper portion. Y 1

In Figs. 6 and 7, I have shown the completed articles, lthe dotted lines inFig. 7 however,.showing how this relatively thick base would bulge if the article had not-,been made by the process above outlined.

From the foregoing, it will be seenthat with the presentjmethod it is possible Jr'or quick production inasmuch as the first heat may be limited toi twenty minutes and', at the same time, there is no possibility of the base bulging or k blowing. as the' gases escape, from the-bleeder hole, as outlined.

It will be understood that the mold may have aV plurality of cavities so Athatva .num-V ber of these articlesl may be molded at the one time and while in the drawing I have shown'a ragmentary'portion ofamold to illustrate the manner in which the method is carried out, it will be understood that there will be a plurality of cavities for making a number of the articles `at theorie time.

Having thus described my invention, 'what I claim as new and desire to secure by Lei-, ters Patent is 1f The method, 0f Prodlwins, e 'h-rd r11-b? ber block which consists in running vulcanizable rubber stock through a tubing machine and forming a relatively large and a relatively small bore in the stock, cutting the stock into blocks, placing cores within said bores, placing the blocks in a mold and subjecting the` molds to heatuandpressure for approximately twenty minutes, removing the cores from the relatively small bores, and

Yvulcanizing the blocks for a period of approximately six and one-half hours.

2. The method of forming a hard rubber article which4` consists in running vulcanizable rubber through a rod and tubing machinel and forming -a relatively large bore and a small bore insaid stock, cutting the stock into blocks', placing a core in the respective bores to respectively form a chamber anda bleeder hole within the block, heating the blocks .under pressure Jfor approximately twenty minutes,'removing only the core from the bleeder hole and subjecting the block to a further heatand pressure for. approximately six and one-half hours, the removal of the core in the bleeder hole permitting the escape ofigases, during the vulcanization to thereby prevent the articleffrom deforming during the vulcanization.

S. vThe method of forming a hard rubber article with a Vrelatively thick base which includes subjecting vulcanizable rubber ystock to arod and tubing machine to form a bore and bleeder .hole in the stock, cutting the stock oil into blocks and placing a, core in the bore and. in the bleeder hole andv subjecting the block to a relatively short heat andpressure to partly cure the same, removing the core'from` the bleeder hole, and subjecting the block to a further heat and pressure for approximately six and one-half hours.

In testimony whereof, I affix my signature.

vISAAC Q. GURNEE. 

